Depth Stops for a Hand-Held Router

When using a router, you want to avoid taking too deep a cut. It can create
excess chipout and, in some situations, can be dangerous. So when I want to
rout a dado or groove that’s more than a ¼″ deep, I take
multiple passes.

I know. It’s easy enough to change the height of the bit between
passes. But with some routers, changing the height of the bit also slightly
changes the position of the bit relative to the base. (This means you could
end up with an unwanted shoulder inside the dado.) And besides, I’ve
come up with a way of using depth stops that lets me avoid the extra
setups.

To rout a deep dado with one setup, I use a set of depth stops or plates
that are carpet taped to the base of the router, refer to Fig. 2 at right.
Two of these plates are made from 1/8″ hardboard, and a third
is 1/16″-thick
plastic laminate. All three stops have a hole drilled in the center for the
bit to fit through.

Before you add the depth stops to the base plate, the first thing to do is
adjust the height of the router bit to match the finished depth of the dado,
as in Fig. 1. (Once the bit is set, leave it alone.) Then carpet tape the
auxiliary stops to the base of the router (Fig. 2).

After the first pass, simply “lower” the bit during successive
passes by removing one stop (Fig. 3). The final pass (after
removing the laminate depth stop) will be a 1/16″-deep skim cut that
will leave a clean dado at just the right depth.